Display device and method of manufacturing the same

ABSTRACT

A display device includes a display panel which includes a bending area which is bendable and includes a curvature area in a bent state, a protective film by which a first groove is defined, where the first groove corresponds to the curvature area, and an adhesive member disposed between the protective film and the display panel. The protective film includes a first inner side surface and a second inner side surface that define the first groove, and the first inner side surface and the second inner side surface have inclined shapes.

This application claims priority to Korean Patent Application No.10-2017-0097274, filed on Jul. 31, 2017, and all the benefits accruingtherefrom under 35 U.S.C. § 119, the content of which in its entirety isherein incorporated by reference.

BACKGROUND 1. Field

Exemplary embodiments of the invention relate to a display device and amethod of manufacturing the same and, more particularly, to a displaydevice with improved bending characteristics and a method ofmanufacturing the same.

2. Description of the Related Art

An electronic device such as a smart phone, a tablet, a notebookcomputer, and a smart television has been developed. This electronicdevice includes a display device to show information. The electronicdevice further includes various electronic modules in addition to thedisplay device.

To realize a slim bezel, the electronic device may include a displaydevice of which a portion is bent.

SUMMARY

Bending stress may be applied to the display device in a process ofbending the display device, and thus faulty products may occur.Exemplary embodiments of the invention may provide a display devicecapable of improving bending characteristics.

Exemplary embodiments of the invention may also provide a method ofmanufacturing a display device, which is capable of improving processefficiency.

According to an exemplary embodiment of the invention, a display deviceincludes a display panel, a protective film, and an adhesive member.

In this case, the display panel includes a non-bending area and abending area which is bendable from the non-bending area, and thebending area includes a curvature area having a predetermined curvatureand a facing area facing the non-bending area in a bent state.

In this case, the protective film is disposed on a rear surface of thedisplay panel and includes a thermoplastic resin, and a first groove isdefined by the protective film and corresponds to the curvature area.

In this case, the adhesive member is disposed between the protectivefilm and the display panel.

In this case, the protective film includes a first inner side surfaceand a second inner side surface that define the first groove, and thefirst inner side surface and the second inner side surface are inclined.

In an exemplary embodiment of the invention, a portion of a rear surfaceof the adhesive member, which corresponds to the curvature area, may beexposed outward.

In an exemplary embodiment, a rear surface of the protective film mayinclude a first rear surface and a second rear surface, and the firstgroove is defined therebetween. The protective film may include a bumpportion that protrudes from the first rear surface and the second rearsurface adjacent to the first groove.

In an exemplary embodiment of the invention, a second groove may bedefined by the adhesive member, and corresponds to the curvature area.In this case, a portion of the rear surface of the display panel, whichcorresponds to the curvature area, may be exposed outward.

In an exemplary embodiment, the display device may further include atleast one pattern disposed on the portion, corresponding to thecurvature area, of the rear surface of the adhesive member.

In an exemplary embodiment, a thickness of the pattern in a thirddirection perpendicular to the rear surface of the adhesive member mayrange from about 20% to about 40% of a thickness of the protective film.The first groove may extend in a first direction, and the pattern may beprovided in plurality.

In an exemplary embodiment, each of the plurality of patterns may extendin a second direction perpendicular to the first direction in astretched-out state, and the patterns may be spaced apart from eachother.

In an exemplary embodiment, each of the plurality of patterns may extendin the first direction, and the patterns may be spaced apart from eachother.

In an exemplary embodiment, the at least one pattern may have ahemispherical shape.

In an exemplary embodiment, the thermoplastic resin may includepolyethylene terepthalate (“PET”).

According to an exemplary embodiment of the invention, a method ofmanufacturing a display device includes providing preliminary displaydevice that comprises a display panel including a first area and asecond area connected to the first area, an adhesive member disposed ona rear surface of the display panel, and a protective film disposed on arear surface of the adhesive member, and pressing the protective filmusing a heating block and removing a partial region, of the protectivefilm, which corresponds to a portion of the second area, where thesecond area is bendable.

In an exemplary embodiment, the protective film may include athermoplastic resin, and the heating block may be heated to atemperature higher than or equal to a sublimation temperature of thethermoplastic resin.

In an exemplary embodiment, a region from which the protective film isremoved may be defined as a groove, the protective film may include afirst inner side surface and a second inner side surface that define thegroove, and the first inner side surface and the second inner sidesurface may have inclined shapes.

In an exemplary embodiment, a region from which the protective film isremoved may be defined as a groove, and pressing of the protective filmusing the heating block may include forming a bump portion protrudingfrom a rear surface of the protective film adjacent to the groove.

In an exemplary embodiment, the method may further include removing thebump portion.

In an exemplary embodiment, a concave portion may be defined at a bottomsurface of the heating block, which comes in contact with a region inwhich the protective film is pressed. In this case, pressing theprotective film may further comprise forming a pattern corresponding tothe concave portion on the rear surface of the adhesive member.

In an exemplary embodiment, pressing the protective film comprisesremoving a partial region, of the adhesive member, which corresponds tothe portion of the second area.

In an exemplary embodiment, the second area in a bent state may includea curvature area having a predetermined curvature and a facing areafacing the first area in a thickness direction of the display panel.Here, the curvature area corresponds to the portion of the second area.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other advantages and features of the invention will becomemore apparent by describing in further detail exemplary embodimentsthereof with reference to the accompanying drawings, in which:

FIG. 1 is a front perspective view illustrating an exemplary embodimentof an electronic device according to the invention.

FIG. 2A is an exploded perspective view illustrating an exemplaryembodiment of a display device according to the invention.

FIG. 2B is a first side view illustrating an exemplary embodiment of adisplay device according to the invention.

FIG. 2C is a second side view illustrating an exemplary embodiment of adisplay device according to the invention.

FIG. 2D is a cross-sectional view illustrating an exemplary embodimentof a display module according to the invention.

FIG. 2E is a rear perspective view illustrating an exemplary embodimentof a display module according to the invention.

FIG. 3A is a cross-sectional view illustrating an exemplary embodimentof a display module according to the invention.

FIG. 3B is a rear perspective view illustrating an exemplary embodimenta display module according to the invention.

FIG. 4A is a cross-sectional view illustrating an exemplary embodiment adisplay module according to the invention.

FIG. 4B is a rear perspective view illustrating an exemplary embodimenta display module according to the invention.

FIG. 5A is a cross-sectional view illustrating an exemplary embodiment adisplay module according to the invention.

FIG. 5B is a rear perspective view illustrating an exemplary embodimenta display module according to the invention.

FIG. 6A is a rear perspective view illustrating an exemplary embodimenta heating block according to the invention.

FIGS. 6B and 6C are side views illustrating an exemplary embodiment amethod of manufacturing a display device according to the invention.

FIG. 6D is a cross-sectional view illustrating an exemplary embodimentof a display device in a process illustrated in FIG. 6C.

FIG. 6E is a cross-sectional view illustrating an exemplary embodimentof a bent display device according to the invention.

FIGS. 7A to 7C show images of bump portions of protective films formedusing heating blocks having different shapes.

FIG. 7D shows images of grooves defined by protective films, formed invariously applied pressures of a heating block.

FIG. 7E shows images of grooves defined by protective films, formed invarious contact times of a heating block.

FIG. 8 is a front perspective view illustrating an exemplary embodimentof a heating block according to the invention.

FIG. 9 is a cross-sectional view illustrating an exemplary embodiment ofa display device manufactured using the heating block of FIG. 8.

DETAILED DESCRIPTION

The invention now will be described more fully hereinafter withreference to the accompanying drawings, in which various exemplaryembodiments are shown. This invention may, however, be embodied in manydifferent forms, and should not be construed as limited to the exemplaryembodiments set forth herein. Rather, these exemplary embodiments areprovided so that this disclosure will be thorough and complete, and willfully convey the scope of the invention to those skilled in the art.Like reference numerals refer to like elements throughout.

It will be understood that when an element such as a layer, region orsubstrate is referred to as being “on” another element, it can bedirectly on the other element or intervening elements may be present. Incontrast, the term “directly” means that there are no interveningelements. As used herein, the term “and/or” includes any and allcombinations of one or more of the associated listed items. Theterminology used herein is for the purpose of describing particularexemplary embodiments only and is not intended to be limiting. As usedherein, the singular forms “a,” “an,” and “the” are intended to includethe plural forms, including “at least one,” unless the content clearlyindicates otherwise. “Or” means “and/or.” As used herein, the term“and/or” includes any and all combinations of one or more of theassociated listed items. It will be further understood that the terms“comprises” and/or “comprising,” or “includes” and/or “including” whenused in this specification, specify the presence of stated features,regions, integers, steps, operations, elements, and/or components, butdo not preclude the presence or addition of one or more other features,regions, integers, steps, operations, elements, components, and/orgroups thereof “About” or “approximately” as used herein is inclusive ofthe stated value and means within an acceptable range of deviation forthe particular value as determined by one of ordinary skill in the art,considering the measurement in question and the error associated withmeasurement of the particular quantity (i.e., the limitations of themeasurement system). For example, “about” can mean within one or morestandard deviations, or within ±30%, 20%, 10% or 5% of the stated value.

Spatially relative terms, such as “beneath”, “below”, “lower”, “above”,“upper” and the like, may be used herein for ease of description todescribe one element or feature's relationship to another element(s) orfeature(s) as illustrated in the figures. It will be understood that thespatially relative terms are intended to encompass differentorientations of the device in use or operation in addition to theorientation depicted in the figures. For example, if the device in thefigures is turned over, elements described as “below” or “beneath” otherelements or features would then be oriented “above” the other elementsor features. Thus, the exemplary term “below” can encompass both anorientation of above and below. The device may be otherwise oriented(rotated 90 degrees or at other orientations) and the spatially relativedescriptors used herein interpreted accordingly. It will be understoodthat, although the terms first, second, etc. may be used herein todescribe various elements, components, regions, layers and/or sections,these elements, components, regions, layers and/or sections should notbe limited by these terms. These terms are only used to distinguish oneelement, component, region, layer or section from another region, layeror section. Thus, a first element, component, region, layer or sectiondiscussed below could be termed a second element, component, region,layer or section without departing from the teachings herein. Exemplaryembodiments are described herein with reference to cross-sectionalillustrations and/or plane illustrations that are idealized exemplaryillustrations. In the drawings, the thicknesses of layers and regionsare exaggerated for clarity. Accordingly, variations from the shapes ofthe illustrations as a result, for example, of manufacturing techniquesand/or tolerances, are to be expected. Thus, exemplary embodimentsshould not be construed as limited to the shapes of regions illustratedherein but are to include deviations in shapes that result, for example,from manufacturing. For example, an etching region illustrated as arectangle will, typically, have rounded or curved features. Thus, theregions illustrated in the figures are schematic in nature and theirshapes are not intended to illustrate the actual shape of a region of adevice and are not intended to limit the scope of exemplary embodiments.

Hereinafter, exemplary embodiments of the invention will be described indetail with reference to the accompanying drawings.

FIG. 1 is a front perspective view illustrating an exemplary embodimentof an electronic device ED according to the invention.

Referring to FIG. 1, a smart phone is illustrated as an electronicdevice ED in this exemplary embodiment. However, an electronic deviceaccording to the invention is not limited thereto. In certain exemplaryembodiments, the electronic device ED may be a tablet, a notebookcomputer, or a smart television.

As illustrated in FIG. 1, a display surface, on which an image IM isdisplayed, is parallel to a plane defined by a first directional axisDR1 and a second directional axis DR2. The display surface may include adisplay area DA and a bezel area BZA adjacent to the display area DA. InFIG. 1, an internet search engine is illustrated as an example of theimage IM. In an exemplary embodiment, for example, the display area DAmay have a quadrilateral shape. The bezel area BZA may surround thedisplay area DA. In other words, the bezel area BZA forms a border ofthe display surface. In certain exemplary embodiments of the invention,the bezel area BZA may be disposed in only two areas opposite to eachother in the first directional axis DR1 or in only two areas opposite toeach other in the second directional axis DR2.

A normal direction of the display surface (i.e., a thickness directionof the electronic device ED) is parallel to a third directional axisDR3. A front surface (different names: a top surface, a first surface)and a rear surface (different names: a bottom surface, a second surface)of each member are defined with respect to a direction in which theimage IM is displayed. That is, a front surface of a member is a surfaceof the member disposed in a direction in which the image IM is displayedin a stretched-out state and a rear surface of the member is an oppositesurface of the member. In other words, among two surfaces of a member, asurface which is closer to the display surface shown in FIG. 1 is afront surface of the member, and a surface which is farther from thedisplay surface is a rear surface of the member in a stretched-outstate. Hereinafter, first to third directions mean the directionsindicated by the first to third directional axes DR1, DR2, and DR3,respectively, and are indicated by the same reference designators as thefirst to third directional axes DR1, DR2, and DR3. Each of the first tothird directions may indicate either direction of two oppositedirections parallel to the corresponding directional axis among thefirst to third directional axes DR1, DR2, and DR3 unless statedotherwise.

The electronic device ED may include a display device DD and an outercase EDC. The display device DD will be described later.

The outer case EDC may be coupled to the display device DD. The outercase EDC may provide an outer surface of the electronic device ED. Inthis exemplary embodiment of FIG. 1, the outer case EDC in one unitarybody is illustrated as an example. However, an outer case according tothe invention are not limited thereto. In an exemplary embodiment, theouter case EDC may include a plurality of bodies assembled with eachother. In an exemplary embodiment, the outer case EDC may include aplurality of frames and/or plates which may include or be formed ofglass, plastic, and/or a metal.

FIG. 2A is an exploded perspective view illustrating an exemplaryembodiment of a display device DD according to the invention. FIG. 2B isa first side view illustrating an exemplary embodiment of the displaydevice DD according to the invention, and FIG. 2C is a second side viewillustrating an exemplary embodiment of the display device DD accordingto the invention. FIG. 2D is a cross-sectional view illustrating anexemplary embodiment of a display module according to the invention, andFIG. 2E is a rear perspective view illustrating an exemplary embodimentof a display module according to the invention. Hereinafter, anexemplary embodiment of the display device DD according to the inventionwill be described with reference to the drawings.

As illustrated in FIGS. 2A to 2C, the display device DD may include awindow member WM and a display module DM. The window member WM includesa base member BS and a bezel layer BZL disposed on a rear surface of thebase member BS. An area in which the bezel layer BZL is disposed may bedefined as the bezel area BZA illustrated in FIG. 1. In this exemplaryembodiment, a flat window member WM is illustrated in the display areaDA. However, the shape of the window member WM may be variouslymodified. In certain exemplary embodiments, edges of the window memberWM, which are opposite to each other in the first direction DR1, mayhave curved surfaces.

The base member BS may include a glass substrate, a sapphire substrate,or a plastic substrate. The base member BS may have a single-layered ormulti-layered structure. In an exemplary embodiment, for example, thebase member BS may include a plurality of plastic films coupled to eachother by an adhesive. In an exemplary embodiment, the base member BS mayinclude a glass substrate and a plastic film coupled to the glasssubstrate by an adhesive member.

The bezel layer BZL may have a single-layered or multi-layeredstructure. In an exemplary embodiment, the multi-layered bezel layer BZLmay include a buffer layer for improving adhesive strength, a patternlayer for providing a predetermined pattern, and an achromatic colorlayer. The pattern layer may provide a pattern referred to as ‘ahairline’. The achromatic color layer may include an organic mixtureincluding a black pigment or dye. The layers included in themulti-layered bezel layer BZL may be formed by a deposition process, aprinting process, and/or a coating process. Even though not shown in thedrawings, the window member WM may further include a functional coatinglayer disposed on a front surface of the base member BS. In an exemplaryembodiment, the functional coating layer may include at least one of ananti-fingerprint layer, an anti-reflection layer, or a hard coatinglayer.

As illustrated in FIGS. 2A to 2C, the display module DM may include adisplay panel DP, an input sensing unit ISU, an anti-reflection unitARU, a protective film PF, and a driving control module DCM. FIG. 2Billustrates the display panel DP that is stretched out, and FIG. 2Cillustrates the display panel DP that is bent.

The display panel DP may be a flexible display panel, for example, anorganic light-emitting display panel. In a plan view, the display panelDP includes a pixel area PXA in which pixels PX are disposed, and anon-pixel area NPXA adjacent to the pixel area PXA. The pixels PX arenot disposed in the non-pixel area NPXA, but peripheral components suchas signal lines and banks are disposed in the non-pixel area NPXA. Thepixel area PXA and the non-pixel area NPXA may correspond to the displayarea DA and the bezel area BZA of FIG. 1, respectively. However, shapesand/or areas of the pixel area PXA and the non-pixel area NPXA may notbe completely the same as those of the display area DA and the bezelarea BZA.

The input sensing unit ISU may obtain coordinate information of anexternal input. The input sensing unit ISU may sense at least one ofvarious kinds of inputs provided from the outside of the electronicdevice ED. In an exemplary embodiment, for example, the input sensingunit ISU may sense an input by a body of a user and/or may sense orrecognize at least one of various external inputs such as light, heat,and pressure. In addition, the input sensing unit ISU may sense aproximity input by getting close to a sensing surface as well as adirect input by contacting the sensing surface.

The anti-reflection unit ARU may include a polarizing film and/or aphase retardation film. The number of the phase retardation film and aphase retardation length (e.g., λ/4 or λ/2) of the phase retardationfilm may be determined depending on an operating principle of theanti-reflection unit ARU. The anti-reflection unit ARU may include colorfilters.

The protective film PF is disposed on a rear surface of the displaypanel DP. In this exemplary embodiment shown in FIG. 2B, a groove GR1(hereinafter, referred to as “a first groove”) corresponding to acurvature area CA is defined in the protective film PF. The first grooveGR1 may extend in the first direction DR1.

The first groove GR1 may be formed by a heating block HB of FIG. 6A. Thefirst groove GR1 is defined as an area from which at least a portion ofthe protective film PF is removed. A process of forming the first grooveGR1 will be described later in more detail.

The protective film PF may include a first protective film PF1 and asecond protective film PF2 that are spaced apart from each other, andthe first groove GR1 is defined therebetween.

The protective film PF may include a plastic film as a base layer. In anexemplary embodiment, the protective film PF may include a plastic filmincluding a thermoplastic resin, for example, one of polyethyleneterepthalate (“PET”), polyethylene (“PE”), polyvinylchloride (“PVC”),polypropylene (“PP”), polystyrene (“PS”), polyacrylonitrile (“PAN”),styrene-acrylonitrile copolymer (“SAN”), acrylonitrile-butadiene-styrene(“ABS”), and polymethyl methacrylate (“PMMA”), or any combinationthereof. In particular, PET has excellent heat resistance and excellentfatigue strength and electrical characteristics and is less affected bytemperature and humidity.

The material of the protective film PF according to the invention is notlimited to the plastic resins, but may include an organic/inorganiccomposite material. In an exemplary embodiment, for example, theprotective film PF may include a porous organic layer and an inorganicmaterial filling pores of the porous organic layer.

The driving control module DCM may include a first circuit substrate (ora driving circuit substrate) MCB, a second circuit substrate FCBconnecting the first circuit substrate MCB to the display panel DP, anda driving chip F-IC mounted on the second circuit substrate FCB. Eventhough not shown in the drawings, a plurality of passive elements andactive elements may be mounted on the first circuit substrate MCB. Thefirst circuit substrate MCB may be a rigid or flexible circuitsubstrate, and the second circuit substrate FCB may be a flexiblecircuit substrate.

In this exemplary embodiment shown in FIG. 2B, the input sensing unitISU and the anti-reflection unit ARU are provided separately.Alternatively, at least one of the input sensing unit ISU and theanti-reflection unit ARU may be omitted. In an exemplary embodiment, atleast one of the input sensing unit ISU and the anti-reflection unit ARUmay be integrated with the display panel DP as a single unitary unit bycontinuous processes of manufacturing.

Hereinafter, the display module DM will be described in more detail withreference to FIGS. 2A to 2E. In an exemplary embodiment, each of firstto fifth adhesive members AM1 to AM5 to be described below may be apressure sensitive adhesive film (“PSA”), an optically clear adhesivefilm (“OCA”), or an optically clear resin (“OCR”). The first to fifthadhesive members AM1 to AM5 may include, but not limited to, aphoto-curing adhesive material or a thermosetting adhesive material. Incertain exemplary embodiments, one or more of the first to fifthadhesive members AM1 to AM5 may be omitted.

The input sensing unit ISU may be disposed on a rear surface of thewindow member WM. The window member WM and the input sensing unit ISUmay be coupled to each other by the first adhesive member AM1 interposedtherebetween. The anti-reflection unit ARU may be disposed on a rearsurface of the input sensing unit ISU. The input sensing unit ISU andthe anti-reflection unit ARU may be coupled to each other by the secondadhesive member AM2 interposed therebetween. The display panel DP may bedisposed on a rear surface of the anti-reflection unit ARU. Theanti-reflection unit ARU and the display panel DP may be coupled to eachother by the third adhesive member AM3 interposed therebetween. Thethird adhesive member AM3 may be thinner than the first adhesive memberAM1 and the second adhesive member AM2. In certain exemplaryembodiments, the positions of the anti-reflection unit ARU and the inputsensing unit ISU may be interchanged.

The display panel DP is illustrated as a single-layered structure inFIGS. 2B and 2C. However, as illustrated in FIG. 2D, the display panelDP may have a multi-layered structure including a base layer BL, acircuit layer CL, an element layer LEL, and an encapsulation layer ECLin an exemplary embodiment.

The base layer BL may be a resin layer and may include, but not limitedto, polyimide (“PI”). The circuit layer CL may be disposed on a frontsurface of the base layer BL. The circuit layer CL may have amulti-layered structure including an insulating layer, a conductivelayer, and a semiconductor layer. The circuit layer CL includes a pixelcircuit including a thin film transistor and signal lines connected tothe pixel circuit.

The element layer LEL may be disposed on a front surface of the circuitlayer CL. The element layer LEL may include a light-emitting element,e.g., an organic light-emitting element. The encapsulation layer ECL isdisposed on the element layer LEL to encapsulate the element layer LEL.The encapsulation layer ECL may have a multi-layered structure includingan organic layer and an inorganic layer, called ‘a thin filmencapsulation (“TFE”)’. In certain exemplary embodiments, theencapsulation layer ECL may include only one of an inorganic layer andan organic layer. In other exemplary embodiments, the display panel DPmay include an encapsulation substrate and a sealant, which aresubstituted for the encapsulation layer ECL. The sealant may couple theencapsulation substrate onto the element layer LEL.

The display panel DP and the protective film PF may be coupled to eachother by the fourth adhesive member AM4 therebetween. A rear surface ofthe base layer BL and the front surface of the protective film PF may becoupled to each other by the fourth adhesive member AM4. The fourthadhesive member AM4 may include a first adhesive portion AM4-1 and asecond adhesive portion AM4-2 that correspond to the first protectivefilm PF1 and the second protective film PF2, respectively.

As illustrated in FIG. 2D, the display panel DP may include two areas.Since the display panel DP is capable to be bent as illustrated in FIG.2C, the display panel DP may include a non-bending area NBA and abending area BA. The bending area BA may include a curvature area CA anda facing area FA. The curvature area CA may have a predeterminedcurvature in the state in which the display panel DP is bent, and thefacing area FA may face the non-bending area NBA in the state in whichthe display panel DP is bent.

The base layer BL and the circuit layer CL may be disposed to correspondto both the non-bending area NBA and the bending area BA. In contrast,the element layer LEL and the encapsulation layer ECL may be disposedonly in the non-bending area NBA.

The first protective film PF1 may correspond to the non-bending areaNBA. The first adhesive portion AM4-1 may couple the non-bending areaNBA of the base layer BL and the first protective film PF1 to eachother. The second protective film PF2 and the second adhesive portionAM4-2 may correspond to the facing area FA. The first protective filmPF1 and the second protective film PF2 are spaced apart from each other,and the first groove GR1 corresponding to the curvature area CA isinterposed between the first protective film PF1 and the secondprotective film PF2.

The first protective film PF1 includes a first inner side surface IS1,and the second protective film PF2 includes a second inner side surfaceIS2. The first groove GR1 is defined by the first and second inner sidesurfaces IS1 and IS2. The first inner side surface IS1 and the secondinner side surface IS2 are spaced apart from each other in the seconddirection DR2 and face each other in the second direction DR2. The firstinner side surface IS1 and the second inner side surface IS2 may beinclined surfaces. A distance between the first and second inner sidesurfaces IS1 and IS2 in the second direction DR2 increases from the rearsurface of the display panel DP in the third direction DR3 which is fromthe fourth adhesive member AM4 to the protective film PF.

The protective film PF may include a bump portion PF-BP protruding froma rear surface of the protective film PF. The bump portion PF-BP mayinclude a first bump portion BP1 protruding from a first rear surfacePF-A1 of the first protective film PF1 and a second bump portion BP2protruding from a second rear surface PF-A2 of the second protectivefilm PF2. The first and second bump portions BP1 and BP2 may be adjacentto the first groove GR1. The first bump portion BP1 and the second bumpportion BP2 may be removed.

The display panel DP may further include a stress control film SCF thatis disposed on the circuit layer CL to correspond to at least thecurvature area CA. In an exemplary embodiment, the stress control filmSCF may be disposed on the display panel DP as a separate member asshown in FIG. 2B. In certain exemplary embodiments, portions of thestress control film SCF may overlap with the non-bending area NBA andthe facing area FA. The stress control film SCF may include a plasticfilm, like the protective film PF. A neutral plane of the curvature areaCA, which is defined in the bending of the display panel DP, may beadjacent to the circuit layer CL by the stress control film SCF.

Referring again to FIGS. 2B and 2C, the curvature area CA may bedisposed between the facing area FA and the non-bending area NBA in thestate in which the display panel DP is stretched out. The facing area FAmay face the non-bending area NBA in the thickness direction DR3 of thedisplay module DM in the state in which the display panel DP is bent. Inthe bent state, a predetermined radius of curvature is defined withrespect to a bending axis BX extending in the first direction DR1 in thebending area BA.

Pads of the circuit layer CL may be aligned with one side of the facingarea FA. The second circuit substrate FCB is connected to the displaypanel DP in the facing area FA. In the bent state, the first circuitsubstrate MCB and the second circuit substrate FCB face the rear surfaceof the display panel DP.

Since the first groove GR1 is defined by the protective film PF ascorresponds to the curvature area CA, it is possible to reduce orminimize stress occurring at the circuit layer CL when the display panelDP is bent.

In an exemplary embodiment of the invention, a second groove GR2 may bedefined by the fourth adhesive member AM4 and correspond to thecurvature area CA. In this case, a portion of the rear surface of thedisplay panel DP, which corresponds to the curvature area CA, may beexposed to the outside. Here, the outside is not the outside of theelectronic device ED but is the outside of the display module DM in aninner space of the electronic device ED. The fourth adhesive member AM4may include the first adhesive portion AM4-1 and the second adhesiveportion AM4-2 which are spaced apart from each other and the secondgroove GR2 is defined therebetween.

The first circuit substrate MCB and the second circuit substrate FCB maybe coupled to each other in the third direction DR3 by a conductivemember CAM and the fifth adhesive member AM5 that are disposed betweenthe first and second circuit substrates MCB and FCB. The conductivemember CAM electrically connects the first and second circuit substratesMCB and FCB to each other and physically couples the first and secondcircuit substrates MCB and FCB to each other. The fifth adhesive memberAM5 may reduce stress which occurs at the conductive member CAM in theprocess of bending the display panel DP.

In some exemplary embodiments of the invention, the protective film PFmay include patterns PT in the curvature area CA (see FIGS. 3A to 5B).The patterns PT may be thinner than the protective film PF in other areaor partially fill the curvature area CA. Hereinafter, the patterns PTwill be described with reference to the drawings.

FIG. 3A is a cross-sectional view illustrating an exemplary embodimentof a display module according to the invention, and FIG. 3B is a rearperspective view illustrating an exemplary embodiment of a displaymodule according to the invention.

Referring to FIGS. 3A and 3B, a portion, corresponding to the curvaturearea CA, of a rear surface of a fourth adhesive member AM4 may beexposed outward by the first groove GR1. Patterns PT may be disposed onthe portion, corresponding to the curvature area CA, of the rear surfaceof the fourth adhesive member AM4. In an exemplary embodiment,thicknesses of the patterns PT in the third direction DR3 may be about30% of a thickness of each of the first and second protective films PF1and PF2.

In this exemplary embodiment, the patterns PT may extend in the seconddirection DR2 and may be spaced apart from each other in the firstdirection DR1. Since the patterns PT extend in the second direction DR2,it is possible to reduce stress that occurs at signal lines crossingover the curvature area CA of the display panel DP in the process ofbending the display panel DP.

The patterns PT may have various shapes and may be variously disposed.Hereinafter, other various shapes and arrangement of the patterns PTwill be described with reference to the drawings.

FIG. 4A is a cross-sectional view illustrating still an exemplaryembodiment of a display module according to the invention, and FIG. 4Bis a rear perspective view illustrating still an exemplary embodiment ofa display module according to the invention. Hereinafter, shapes ofpatterns PT will be described.

Referring to FIGS. 4A and 4B, patterns PT may extend in the firstdirection DR1 and may be spaced apart from each other in the seconddirection DR2. The patterns PT according to this exemplary embodimentmay reduce stress that occurs at signal lines corresponding to thecurvature area CA of the display panel DP in the process of bending thedisplay panel DP.

FIG. 5A is a cross-sectional view illustrating still an exemplaryembodiment of a display module according to the invention, and FIG. 5Bis a rear perspective view illustrating still an exemplary embodiment ofa display module according to the invention.

Referring to FIGS. 5A and 5B, patterns PT may have hemispherical shapes.However, shapes of the patterns PT according to the invention are notlimited thereto. In certain exemplary embodiments, the patterns PT mayhave polygonal three-dimensional shapes. The patterns PT according tothis exemplary embodiment may reduce stress that occurs at signal linescorresponding to the curvature area CA of the display panel DP in theprocess of bending the display panel DP.

FIG. 6A is a rear perspective view illustrating an exemplary embodimentof a heating block according to the invention, and FIGS. 6B and 6C areside views illustrating an exemplary embodiment of a method ofmanufacturing a display device according to the invention.

FIG. 6D is a cross-sectional view illustrating an exemplary embodimentof a display device in a process illustrated in FIG. 6C.

The heating block HB illustrated in FIG. 6A may include a metal pillarhaving a bar shape. The heating block HB may include stainless steelhaving excellent strength and durability or may include aluminum orcopper having high thermal conductivity. A length of the heating blockHB in an extending direction (e.g., DR1) of the heating block HB may belonger or shorter than a length of the display device DD (see FIG. 2A)in the first direction DR1.

As illustrated in FIG. 6B, the heating block HB is aligned with apreliminary display device The preliminary display device may be thedisplay device DD may be described with reference to FIGS. 2A to 2C.However, in the preliminary display device, the protective film PFcovers an entire portion of the rear surface of the display panel DP anda groove is not defined yet. The heating block HB is heated to apredetermined temperature after being aligned with the preliminarydisplay device.

As illustrated in FIG. 6C, the heating block HB presses the protectivefilm PF to remove a portion of the protective film PF. The heating blockHB may press the protective film PF in a state in which the heatingblock HB is heated to a temperature higher than or equal to asublimation temperature of the protective film PF. In an exemplaryembodiment, for example, when a PET film is used as the protective filmPF, the heating block HB may be heated to a temperature higher than 250degrees Celsius to be used in this process.

A maximum temperature of the heating block HB may be set inconsideration of the base layer BL of the display panel DP. The heatingtemperature of the heating block HB may be set as a temperature at whichthe protective film PF is sublimated but thermal damage of the baselayer BL does not occur. When the base layer BL includes polyimide, themaximum heating temperature of the heating block HB may be lower than600 degrees Celsius.

FIG. 6D illustrates the display device DD from which the heating blockHB is removed. The protective film PF may include the first bump portionBP1 and the second bump portion BP2 which protrude from the first rearsurface PF-Al and the second rear surface PF-A2, respectively. The firstand second bump portions BP1 and BP2 may be adjacent to the first grooveGR1. While the protective film PF is sublimated, the plastic resin ofthe protective film PF may be accumulated on the first rear surfacePF-A1 and the second rear surface PF-A2 of which temperatures arerelatively low, and thus the first and second bump portions BP1 and BP2may be formed.

In certain exemplary embodiments, even though not shown in the drawings,the bump portion PF-BP may be removed by a mechanical polishing process,a chemical polishing process, or a mechanical chemical polishingprocess.

The first and second inner side surfaces IS1 and IS2 of the protectivefilm PF may be inclined with respect to the rear surface of the displaypanel DP. The first inner side surface IS1 and the second inner sidesurface IS2 may be linearly and/or nonlinearly inclined, and profiles ofthe first and second inner side surfaces IS1 and IS2 may be determinedby the shape of the heating block HB.

An adhesive member AM by which a second groove GR2 is defined isillustrated as an example in FIG. 6D. Here, inner side surfaces of theadhesive member AM, which define the second groove GR2, may be coveredby the protective film PF. Thus, the inner side surfaces of the adhesivemember AM may not be exposed outward. The adhesive member AM in FIG. 6Dmay correspond to the fourth adhesive member AM4 described withreference to FIGS. 2A to 2E.

A sum of heights of the first and second grooves GR1 and GR2 in thethird direction DR3 may correspond to a sum of a thickness of theadhesive member AM and a thickness of the protective film PF. The sum ofheights of the first and second grooves GR1 and GR2 in the thirddirection DR3 may range from 50 μm to 100 μm. At this time, a height ofthe display panel DP in the third direction DR3 may range from 20 μm to50 μm. A width of the first groove GR1 in the second direction DR2 mayrange from 1 mm to 2 mm.

FIG. 6E illustrates a display device DD in a bent state. The displaydevice DD may include a first area AR1 and a second area AR2 including aportion in which the first groove GR1 is defined. Here, the secondregion AR2 may correspond to the bending area BA illustrated in FIGS. 2Ato 2E, and the first region AR1 may correspond to the non-bending areaNBA illustrated in FIGS. 2A to 2E.

The display device DD is bent such that a portion corresponding to thefirst groove GR1 has a predetermined curvature. Here, the portion of thedisplay device DD corresponding to the first groove GR1 may correspondto the curvature area CA illustrated in FIGS. 2A to 2E, and a remainingportion of the second area AR2 of the display device DD may correspondto the facing area FA illustrated in FIG. 2A to 2E.

FIGS. 7A to 7C show images of bump portions PF-BP of protective films PFformed using heating blocks HB having different shapes. FIG. 7D showsimages of grooves GR1 defined by protective films PF, formed invariously applied pressures of a heating block HB. FIG. 7E shows imagesof grooves GR1 defined by protective films PF, formed in various contacttimes of a heating block HB.

FIGS. 7A to 7C show various images corresponding to a cross section,defined by the second direction DR2 and the third direction DR3, of theheating block HB of FIG. 6A. As illustrated in FIGS. 7A to 7C, theprofiles of the first inner side surface IS1 and the second inner sidesurface IS2 may be changed depending on a cross-sectional shape of acontact portion HB-C of the heating block HB.

As illustrated in FIG. 7A, when the cross section of the contact portionHB-C of the heating block HB has a rectangular shape, a cross section ofthe first inner side surface IS1 may be inclined and may have a concaveportion. As illustrated in FIG. 7B, when the cross section of thecontact portion HB-C of the heating block HB has a curved portion, across section of the second inner side surface IS2 may have a curvedline. As illustrated in FIG. 7C, when the cross section of the contactportion HB-C of the heating block HB has a stepped structure, a crosssection of the first inner side surface IS1 may have a stepped shape.

As illustrated in FIG. 7D, a roughness of a bottom surface of thegrooves GR1 and GR2 may be changed depending on the applied pressure ofthe heating block HB of the same shape. This is because a degree ofremoval of the protective film PF and the adhesive member AM is changedaccording to the applied pressure of the heating block HB. In anexemplary embodiment, the roughness of the bottom surface may besubstantially constant when the applied pressure of the heating block HBis equal to or greater than 3 Kgf (kilogram-force).

FIG. 7E show images of grooves GR1 formed in various contact times ofthe heating block HB of the same shape. In an exemplary embodiment, in acontact time range of 0.5 sec or less, widths and heights of the bumpportions PF-BP were substantially equal to each other even though thecontact time is changed.

FIG. 8 is a front perspective view illustrating an exemplary embodimentof a heating block according to the invention, and FIG. 9 is across-sectional view illustrating an exemplary embodiment of a displaydevice manufactured using the heating block of FIG. 8.

Referring to FIG. 8, concave portions CC may be defined at a bottomsurface H-BS of a contact portion HB-C of a heating block HB. Theconcave portions CC are defined as areas from which portions of theheating block HB in the third direction DR3 are removed.

The concave portions CC may have shapes and areas which correspond tothose of the patterns PT (see FIGS. 3A to 5B). In FIG. 8, the concaveportions CC extend in the second direction DR2 and are spaced apart fromeach other in the first direction DR1. However, in certain exemplaryembodiments, the shapes of the concave portions CC may be variouslymodified.

As illustrated in FIG. 9, the protective film PF may be pressed by theheating block HB having the concave portions CC, and thus patterns PTcorresponding to the concave portions CC may be formed.

In an exemplary embodiment of the invention, the protective film PF of aunitary body may be adhered to the rear surface of the display panel DP,and then, the protective film PF may be pressed by the heating block HBto form the first groove GR1. Thus, the process of the invention may besimplified as compared with a process of adhering the first protectivefilm PF1 and the second protective film PF2, respectively.

The display device according to an exemplary embodiment of the inventioncan reduce the stress applied to the portion corresponding to thecurvature area of the display panel.

In the method of manufacturing the display device according to anexemplary embodiment of the invention, a portion of an underlying film,which corresponds to the curvature area, may be processed using theheating block. Thus, the manufacturing processes can be simplified.

While the invention has been described with reference to exemplaryembodiments, it will be apparent to those skilled in the art thatvarious changes and modifications may be made without departing from thespirits and scopes of the invention. Therefore, it should be understoodthat the above exemplary embodiments are not limiting, but illustrative.Thus, the scopes of the invention are to be determined by the broadestpermissible interpretation of the following claims and theirequivalents, and shall not be restricted or limited by the foregoingdescription.

What is claimed is:
 1. A display device comprising: a display panel which includes a non-bending area and a bending area which is bendable from the non-bending area, wherein the bending area includes a curvature area having a predetermined curvature and a facing area facing the non-bending area in a bent state; a protective film disposed on a rear surface of the display panel and which includes a thermoplastic resin, wherein a first groove is defined by the protective film and corresponds to the curvature area; and an adhesive member disposed between the protective film and the display panel, wherein the protective film includes a first inner side surface and a second inner side surface that define the first groove, and wherein the first inner side surface and the second inner side surface are inclined.
 2. The display device of claim 1, wherein a rear surface of the protective film includes a first rear surface and a second rear surface, and the first groove is defined therebetween, and wherein the protective film includes a bump portion that protrudes from the first rear surface and the second rear surface adjacent to the first groove.
 3. The display device of claim 1, wherein a second groove is defined by the adhesive member, and corresponds to the curvature area.
 4. The display device of claim 3, wherein a portion of the rear surface of the display panel, which corresponds to the curvature area, is exposed outward.
 5. The display device of claim 1, wherein a portion of a rear surface of the adhesive member, which corresponds to the curvature area, is exposed outward.
 6. The display device of claim 5, further comprising: at least one pattern disposed on the portion, corresponding to the curvature area, of the rear surface of the adhesive member.
 7. The display device of claim 6, wherein a thickness of the pattern ranges from about 20 percentages to about 40 percentages of a thickness of the protective film.
 8. The display device of claim 6, wherein the first groove extends in a first direction, wherein the pattern is provided in plurality, wherein each of the plurality of patterns extends in a second direction perpendicular to the first direction in a stretched-out state, and wherein the patterns are spaced apart from each other.
 9. The display device of claim 6, wherein the first groove extends in a first direction, wherein the pattern is provided in plurality, wherein each of the plurality of patterns extends in the first direction, and wherein the patterns are spaced apart from each other.
 10. The display device of claim 6, wherein the at least one pattern has a hemispherical shape.
 11. The display device of claim 1, wherein the thermoplastic resin includes polyethylene terepthalate (PET).
 12. A method of manufacturing a display device, the method comprising: providing preliminary display device that comprise a display panel including a first area and a second area connected to the first area, an adhesive member disposed on a rear surface of the display panel, and a protective film disposed on a rear surface of the adhesive member; and pressing the protective film using a heating block and removing a partial region, of the protective film, which corresponds to a portion of the second area, wherein the second area is bendable.
 13. The method of claim 12, wherein the protective film includes a thermoplastic resin, and wherein the heating block is heated to a temperature higher than or equal to a sublimation temperature of the thermoplastic resin.
 14. The method of claim 12, wherein a region from which the protective film is removed is defined as a groove, wherein the protective film includes a first inner side surface and a second inner side surface that define the groove, and wherein the first inner side surface and the second inner side surface are inclined.
 15. The method of claim 12, wherein a region from which the protective film is removed is defined as a groove, wherein pressing the protective film using the heating block comprises forming a bump portion protruding from a rear surface of the protective film adjacent to the groove.
 16. The method of claim 15, further comprising: removing the bump portion.
 17. The method of claim 15, wherein a concave portion is defined at a bottom surface of the heating block, which comes in contact with a region in which the protective film is pressed.
 18. The method of claim 17, wherein pressing the protective film further comprises forming a pattern corresponding to the concave portion on the rear surface of the adhesive member.
 19. The method of claim 12, wherein pressing the protective film comprises removing a partial region, of the adhesive member, which corresponds to the portion of the second area.
 20. The method of claim 12, wherein the second area in a bent state comprises a curvature area having a predetermined curvature, and a facing area facing the first area in a thickness direction of the display panel. 